WKWebView swipe back sometimes freezes application

[biesbjerg]

Ionic version: (check one with "x")
[ ] 1.x
[x] 2.x

I'm submitting a ... (check one with "x")
[x] bug report
[ ] feature request
[ ] support request => Please do not submit support requests here, use one of these channels: https://forum.ionicframework.com/ or http://ionicworldwide.herokuapp.com/

Current behavior:
Using WKWebView, when swiping to go back, sometimes the app stops responding to further interaction. No errors are thrown in Xcode console. Sometimes it happens after trying swiping back 3 times, other times it happens after 50 tries - haven't been able to reproduce it reliably.

Steps to reproduce:

1. Tap an item in a list
2. Swipe to go back
3. Repeat until app stops responding

Ionic info: (run ionic info from a terminal/cmd prompt and paste output below):

Cordova CLI: 6.4.0
Ionic CLI Version: 2.1.13
Ionic App Lib Version: 2.1.7
ios-deploy version: 1.9.0
ios-sim version: 5.0.11
OS: macOS Sierra
Node Version: v6.9.1
Xcode version: Xcode 8.1 Build version 8B62

[biesbjerg]

When inspecting the connected device, when the app is in this "crashed state", I see ion-app has the class disable-scroll. If I remove this class, the app starts responding again.

Seems like somehow it is not detecting when swipe has ended?

[biesbjerg]

Xcode log, leading up to a non-responding app:

2016-11-26 18:42:58.903143 Mindly[5849:1452733] App Root: Scroll Disable Assist true
2016-11-26 18:42:58.903436 Mindly[5849:1452733] CDVWKWebViewEngine: handleStopScroll
2016-11-26 18:42:59.068220 Mindly[5849:1452733] App Root: Scroll Disable Assist false
2016-11-26 18:43:02.108085 Mindly[5849:1452733] App Root: Scroll Disable Assist true
2016-11-26 18:43:02.108876 Mindly[5849:1452733] CDVWKWebViewEngine: handleStopScroll
2016-11-26 18:43:02.214207 Mindly[5849:1452733] App Root: Scroll Disable Assist false
2016-11-26 18:43:02.952600 Mindly[5849:1452733] App Root: Scroll Disable Assist true
2016-11-26 18:43:02.960048 Mindly[5849:1452733] CDVWKWebViewEngine: handleStopScroll
2016-11-26 18:43:03.106176 Mindly[5849:1452733] App Root: Scroll Disable Assist false
2016-11-26 18:43:06.153508 Mindly[5849:1452733] App Root: Scroll Disable Assist true
2016-11-26 18:43:06.154071 Mindly[5849:1452733] CDVWKWebViewEngine: handleStopScroll
2016-11-26 18:43:06.253049 Mindly[5849:1452733] App Root: Scroll Disable Assist false
2016-11-26 18:43:09.897074 Mindly[5849:1452733] App Root: Scroll Disable Assist true
2016-11-26 18:43:09.897256 Mindly[5849:1452733] CDVWKWebViewEngine: handleStopScroll
2016-11-26 18:43:09.956330 Mindly[5849:1452733] App Root: Scroll Disable Assist false

[manucorporat]

@biesbjerg thanks very much for your debugging effort! I might know what is going on!

[biesbjerg]

Hmm, I managed to crash it, and when inspecting the html the disable-scroll was not present, so not really sure what's going on.

[manucorporat]

@biesbjerg I just pushed a possible fix to this issue, but I will leave this open until verification

[manucorporat]

Framework side: 177a089
Plugin side: ionic-team/cordova-plugin-wkwebview-engine@4276f7e

[biesbjerg]

So far so good, @manucorporat!

It seems to be working now.
Thank you for fixing this so fast!

[manucorporat]

@biesbjerg awesome! I released a new nightly version, in case you want to test easily in one of your apps.